[EXT] Re: [PATCH v13 02/13] media:Add nv12mt_8l128 and nv12mt_10be_8l128 video format.
Ming Qian
ming.qian at nxp.com
Thu Dec 2 02:02:09 PST 2021
> -----Original Message-----
> From: Hans Verkuil [mailto:hverkuil-cisco at xs4all.nl]
> Sent: Thursday, December 2, 2021 5:40 PM
> To: Ming Qian <ming.qian at nxp.com>; mchehab at kernel.org;
> shawnguo at kernel.org; robh+dt at kernel.org; s.hauer at pengutronix.de
> Cc: kernel at pengutronix.de; festevam at gmail.com; dl-linux-imx
> <linux-imx at nxp.com>; Aisheng Dong <aisheng.dong at nxp.com>;
> linux-media at vger.kernel.org; linux-kernel at vger.kernel.org;
> devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org
> Subject: [EXT] Re: [PATCH v13 02/13] media:Add nv12mt_8l128 and
> nv12mt_10be_8l128 video format.
>
> Caution: EXT Email
>
> On 30/11/2021 10:48, Ming Qian wrote:
> > nv12mt_8l128 is 8-bit tiled nv12 format used by amphion decoder.
> > nv12mt_10be_8l128 is 10-bit tiled format used by amphion decoder.
> > The tile size is 8x128
> >
> > Signed-off-by: Ming Qian <ming.qian at nxp.com>
> > Signed-off-by: Shijie Qin <shijie.qin at nxp.com>
> > Signed-off-by: Zhou Peng <eagle.zhou at nxp.com>
> > ---
> > .../userspace-api/media/v4l/pixfmt-yuv-planar.rst | 15 +++++++++++++++
> > drivers/media/v4l2-core/v4l2-ioctl.c | 2 ++
> > include/uapi/linux/videodev2.h | 2 ++
> > 3 files changed, 19 insertions(+)
> >
> > diff --git
> > a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> > b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> > index 3a09d93d405b..fc3baa2753ab 100644
> > --- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> > +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> > @@ -257,6 +257,8 @@ of the luma plane.
> > .. _V4L2-PIX-FMT-NV12-4L4:
> > .. _V4L2-PIX-FMT-NV12-16L16:
> > .. _V4L2-PIX-FMT-NV12-32L32:
> > +.. _V4L2_PIX_FMT_NV12MT_8L128:
> > +.. _V4L2_PIX_FMT_NV12MT_10BE_8L128:
> >
> > Tiled NV12
> > ----------
> > @@ -296,6 +298,19 @@ tiles linearly in memory. The line stride and
> > image height must be aligned to a multiple of 32. The layouts of the
> > luma and chroma planes are identical.
> >
> > +``V4L2_PIX_FMT_NV12MT_8L128`` is similar to ``V4L2_PIX_FMT_NV12M``
> > +but stores pixel in 2D 8x128 tiles, and stores tiles linearly in memory.
>
> pixel -> pixels (note: also wrong in the text
> V4L2_PIX_FMT_NV12_4L4/16L16/32L32)
>
> Shouldn't this be called V4L2_PIX_FMT_NV12M_8L128? The 'MT' suffix seems
> to be specific to macroblock tiles and not linear tiles.
I'll change it, I thought the t means tiled
>
> > +The image height must be aligned to a multiple of 128.
> > +The layouts of the luma and chroma planes are identical.
> > +
> > +``V4L2_PIX_FMT_NV12MT_10BE_8L128`` is similar to
> > +``V4L2_PIX_FMT_NV12M`` but stores
> > +10 bits pixel in 2D 8x128 tiles, and stores tiles linearly in memory.
> > +the data is arranged at the big end.
>
> at the big end -> in big endian order
>
> I assume the 10 bit pixels are packed? So 5 bytes contain 4 10-bit pixels layout
> like this (for luma):
>
> byte 0: Y0(bits 9-2)
> byte 1: Y0(bits 1-0) Y1(bits 9-4)
> byte 2: Y1(bits 3-0) Y2(bits 9-6)
> byte 3: Y2(bits 5-0) Y3(bits 9-8)
> byte 4: Y3(bits 7-0)
>
> > +The image height must be aligned to a multiple of 128.
> > +The layouts of the luma and chroma planes are identical.
> > +Note the tile size is 8bytes multiplied by 128 bytes, it means that
> > +the low bits and high bits of one pixel may be in differnt tiles.
>
> differnt -> different
>
Got it
> > +
> > .. _nv12mt:
> >
> > .. kernel-figure:: nv12mt.svg
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c
> > b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index 69b74d0e8a90..400eec0157a7 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -1388,6 +1388,8 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc
> *fmt)
> > case V4L2_META_FMT_VIVID: descr = "Vivid Metadata";
> break;
> > case V4L2_META_FMT_RK_ISP1_PARAMS: descr = "Rockchip
> ISP1 3A Parameters"; break;
> > case V4L2_META_FMT_RK_ISP1_STAT_3A: descr = "Rockchip
> ISP1 3A Statistics"; break;
> > + case V4L2_PIX_FMT_NV12MT_8L128: descr = "NV12M (8x128
> Linear)"; break;
> > + case V4L2_PIX_FMT_NV12MT_10BE_8L128: descr = "NV12M
> 10BE(8x128 Linear)"; break;
>
> "10-bit NV12M (8x128 Linear, BE)"
>
> >
> > default:
> > /* Compressed formats */ diff --git
> > a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index f118fe7a9f58..9443c3109928 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -632,6 +632,8 @@ struct v4l2_pix_format {
> > /* Tiled YUV formats, non contiguous planes */ #define
> > V4L2_PIX_FMT_NV12MT v4l2_fourcc('T', 'M', '1', '2') /* 12 Y/CbCr
> > 4:2:0 64x32 tiles */ #define V4L2_PIX_FMT_NV12MT_16X16
> > v4l2_fourcc('V', 'M', '1', '2') /* 12 Y/CbCr 4:2:0 16x16 tiles */
> > +#define V4L2_PIX_FMT_NV12MT_8L128 v4l2_fourcc('N', 'A', '1', '2')
> /* Y/CbCr 4:2:0 8x128 tiles */
> > +#define V4L2_PIX_FMT_NV12MT_10BE_8L128 v4l2_fourcc('N', 'T', '1',
> > +'2') /* Y/CbCr 4:2:0 10-bit 8x128 tiles */
>
> Use v4l2_fourcc_be to denote that this is a BE format.
>
> >
> > /* Bayer formats - see
> > https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.s
> >
> iliconimaging.com%2FRGB%2520Bayer.htm&data=04%7C01%7Cming.qia
> n%40n
> >
> xp.com%7Ce303b4acc4c7478171bc08d9b577abe4%7C686ea1d3bc2b4c6fa92
> cd99c5c
> >
> 301635%7C0%7C0%7C637740347869679174%7CUnknown%7CTWFpbGZsb3
> d8eyJWIjoiMC
> >
> 4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sd
> >
> ata=DJGu6nhkZwiJlVD7oqXG0ZUOGBMmrILtiYirX87MyEo%3D&reserved=
> 0 */
> > #define V4L2_PIX_FMT_SBGGR8 v4l2_fourcc('B', 'A', '8', '1') /* 8
> > BGBG.. GRGR.. */
> >
>
> Regards,
>
> Hans
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